Suction valve

ABSTRACT

A suction valve be placed in a pipe line and intended for flow material, by means of which the flow can be closed, regulated and back flow prevented, whereby the suction valve comprises a movable a locking means ( 3 ) placed in a valve house ( 1 ) and for it a counter face in the valve house and said locking means ( 3 ) can be moved by means of the pressure of the flow material by forming locking means ( 3 ) to be as piston parts or cylinder parts in the working cylinder The pressure of flow material necessary for moving locking means ( 3 ) is led into said locking means through an outlet valve ( 8,9, 10 ), which outlet valve is fitted inside the locking means ( 3 ).

The invention relates to a suction valve to be placed in a pipe line andintended for flow material, by means of which the flow can be closed,regulated and back flow prevented, whereby the suction valve comprises amovable locking means placed in the valve house and for it a counterface in the valve house and said locking means can be moved by means ofthe pressure of the flow material by forming the locking means to be aspiston parts or cylinder parts in the working cylinder. The valve isespecially suited as a suction valve for screw and rotor compressors,which causes quite a small loss of flow and can be regulated and whichcloses as needed. By closing the suction valve the back flow from thecompressor is prevented when the compressor stops.

Previously known is, among others, a suction valve from U.S. Pat. No.6,695,007, where the flow of medium keeps the valve open. When the flowreduces, or for instance, while the suction effect of the compressorlessens, the spring in the valve pulls the closing means against theseat surface and closes the valve. In such a spring-return valve alittle more pressure loss always builds up, because, by means of theflow, the valve-closing means is kept open. Pressure loss builds up evenif the spring would be as to its counter force quite week. When ratherbig compressors are working almost day and night, so already the slightdeterioration of the operating efficiency, because of their suctionvalve, becomes a remarkable expense in the production of compressed air.In addition, it is difficult to regulate a suction valve returning byspring force into intermediate position near the closing state in orderto achieve the relief state of compressor. Thus the relief must be donein closing the valve, while the compressor is working, which takes placeeither in adding the spring back factor or otherwise moving the closingmeans against the closing surface.

In order to improve the presented disadvantages and to achieve bycompressor use, as to its flow loss a very small suction valve, a newsuction valve intended for flow material is developed, which can beplaced in a pipe line and the closing means of which can be moved bymeans of the pressure of the flow material in forming the closing meansto be as a piston or a cylinder part in a working cylinder whichoperates by means of the pressure of the flow material. The abovepresented invention is characterized in that necessary pressure of theflow material is led into said closing means through the outlet valvefitted inside the closing means.

The advantage of the invention is that the keeping of the valve open itdoes not cause any flow loss in the valve. The valve remains open bothdue to its mass by means of force of gravity and by means of thecompressor's suction pressure, said pressure is allowed to impact in acylinder space formed by closing means into a direction pulling theclosing means into open position. The compressor must only one time suckthe negative pressure through the outlet valve into said space, andafterwards no loss on keeping the valve open takes place. Control of theoutlet valve fitted inside the closing means of the suction valve takesplace with the pressure of medium led to it. Closing and opening of thesuction valve is steered to take place by pressurized available medium.Thus control takes place in spite of the compressor running. When theclosing valve is as to its inlet opening installed upwards, the closingmeans facilitates by means of its own mass the opening of the suctionvalve. The closing means can also be regulated to any intermediate placebetween close and open positions. By means of the outlet valve motionsfrom closed state to open state of the closing means can be made quitefast, when the pressure of medium that presses the closing means to theclosed position discharges fast through the outlet valve to the suctiontube of the compressor. The suction valve causes very little pressureloss to the flow passing it, since it is possible to make the formattingof the income and exit sides very streamlined.

In the following the invention is disclosed with reference to theenclosed drawing, where

FIG. 1 shows a section view from the side of the valve open according tothe invention.

FIG. 2 shows the valve in closed position,

FIG. 3 the valve connection diagrammatically.

FIG. 1 shows a suction valve, the outer casing of which is formed of twojoined parts 1 a and 1 b, which can be attached to each other with boltsthrough holes 6. Connected to other part 1 b, by means of wings 2 ledacross the circular flow channel, the fixed circular sleeve-like portion4 of the closing means is fixed, the outer surface of which is fitted towork as a sliding surface together with part 3. Parts 3 and 4 are like acylinder and a piston, which move in regard to each other. Part 3 isfurnished with packing 11 and nestles in closing situation against thecounter surface of part 1 a, while packing 11 is compressing closing. Awing 2, which connects portion 4 to part 1 b is a little thicker,whereby it is possible to lead through it a channel 5 from the outsideinto the part 4.

The outlet valve is fixed inside sleeve-like part 4 by threaded coupling12. The outlet valve has a tap hole 7, which leads directly to thesuction space of the compressor. Furthermore, it comprises in thecylindrical frame 8 of the valve moving a closing flange 10, which is offlexible material, as polyurethane. To the frame 8 a supporting flange 9is connected. The closing flange 10 closes tap hole 7, if the pressurebehind the closing flange 10, led along channel 5 and further along 13,is greater than the pressure in the tap hole 7. The pressure of the taphole 7 dominates also inside closing means 3 and part 4 in the cylinderspace. In the state described in the FIG. 1 no pressure is led throughthe channel 5 to the outlet valve. For instance, channel 5 can also bejoined to same pressure with the compressor suction side, in other wordsto a chamber into which the tap hole 7 discharges. The closing means 3stays in the state shown by FIG. 1 and does not try get closed. Thus theflow losses caused by the closing means are minimized.

The situation of FIG. 2 can be reached both on compressor stopping andworking. For instance, from the compressor's pressure side controlpressure is led behind the closing flange 10 of the outlet valve,whereby it moves to close the tap hole 7. The material of closing flange10 gives in, so that pressure can get, by the way of the flexing outeredge of flange 10, into the cylinder space to circulate inside theclosing means 3, and the pressure pushes the closing means 3 to closedposition. Now the compressor runs relieved or it is stopped. Thepressure cannot get discharged backward off the compressor.

If wanted to get the suction valve open, it happens very fast, since thecontrol pressure of channel 5 is led out, which is a very small amountof air. Then in the cylinder space the pressure from the inside of theclosing means 3 is at once able to push closing flange 10 of the closingmeans 3 a little to the left, whereby the pressure from the inside ofthe closing means 3 quickly discharges through the tap hole 7 into thesuction space of the starting compressor and the closing flange 10remains in the position shown by FIG. 1. Inside the closing means 3negative pressure sucked by the compressor arises and the closing means3 move quickly to open-position and the flow can pass the valve. So therunning of the compressor or its starting accelerates the opening ofvalve. Further, the opening of valve is especially accelerated by theposition of the suction valve, if it is according to the FIGS. 1 and 2,whereby the closing means 3 moves downward to open-position, assisted byforce of gravity.

It is also possible to get for the closing means 3 adjusted intermediatepositions in the position of the quick outlet valve according to FIG. 2by leading through channel 5 only a regulated amount of medium into thespace formed between the closing means 3 and the part 4.

FIG. 3 shows the main diagram of the valve. Valve 14 is a suction valve,comprising in FIGS. 1 and 2 parts 1 a and 3. Valve 15 is an outlet valvecomprising in FIGS. 1 and 2 parts 8, 9 and 10. Valve 16 is a controlvalve, by means of the opening of which the pressure is led to theoutlet valve 15 and this causes that the suction valve 14 closes inspite of the running of compressor 12. The control pressure runs throughthe outlet valve into the closing means 3 and lifts up the closing meansand the suction valve closes. When the pressure control of the valve 16is removed, the low pressure or suction in the suction line 13 leadingto the compressor, removes pressure from the inside of the closing means3, and it gets down, which situation is the open position of the suctionvalve. The pressure line starting from compressor 12 has the referencenumber 17. The inlet opening of the suction valve in the diagram shownin FIG. 3 is described by the reference number 14. From compressor 13pressure line 17 control pressure can be taken to the valve 16. It isalso possible to take control pressure from some other outside pressuresource.

1. A suction valve to be placed in a pipe line and intended for flowmaterial, by means of which the flow can be closed, regulated and backflow prevented, whereby the suction valve comprises movable lockingmeans (3) placed in a valve house (1) and for it a counter face in thevalve house and said locking means (3) can be moved by means of thepressure of the flow material by forming locking means (3) to be aspiston parts or cylinder parts in the working cylinder, characterized inthat the pressure of flow material, necessary for moving locking means(3), is led into said locking means through an outlet valve (8, 9, 10),which outlet valve is fitted inside the locking means (3).
 2. A suctionvalve according to claim 1, characterized in that by selected assemblyposition of the valve, force of gravity is utilized easing andaccelerating the opening of the valve.
 3. A suction valve according toclaim 1, characterized in that the pressure of the steering flowmaterial, led to the outlet valve, is fitted to close an outlet tap hole(7), for instance by means of closing flap (10) that moves by means ofpressure, so that the closing means (3) would move into closing state bymeans of said flow material.
 4. A suction valve according to claim 1,characterized in that reduction of the flow material pressure led to theoutlet valve is fitted to open the tap hole (7) of outlet valve(8),(9),(10) for fast opening of the closing means (3).
 5. A suctionvalve according to claim 1, characterized in that the tap hole of theoutlet valve (8),(9),(10) is fitted to get open into the subsequent pipeline of the suction valve seen from the flow direction.
 6. A suctionvalve according to claim 1, characterized in that the closing means (3)is a moving cylinder, which is fitted to move in regard to sleeve-likepiston (4).
 7. A suction valve according to claim 1, characterized inthat the outlet valve (8),(9), (10) is fitted inside the sleeve-likepiston (4).